1. Technical Field of the Invention
The present invention relates to an X-ray metering apparatus and an X-ray metering method that measure an X-ray generated by inverse Compton scattering by colliding an electron beam with laser light.
2. Description of the Related Art
As means for generating an X-ray by a small-sized device, there is known an X-ray generator capable of obtaining a monochromatic X-ray arisen from inverse Compton scattering by a collision between an electron beam and laser light.
As an example of the X-ray generator, contents disclosed in the following Patent Document 1 are illustrated in FIG. 1. The X-ray generator illustrated in FIG. 1 includes an electron beam generator 52 which accelerates a pulse electron beam 51 and passes the beam through a predetermined rectilinear orbit 50; a laser generator 53 which generates pulse laser light 66; a synchronizer 54 which acquires synchronization between the electron beam generator 52 and the laser generator 53; and a laser light introduction unit 55 which introduces the pulse laser light 66 onto the rectilinear orbit 50 to be opposed to the pulse electron beam 51. The electron beam generator 52 has an RF electron gun 56, an α-magnet 57, an acceleration tube 58, a bending magnet 59, a deceleration tube 60, and a beam dump 61. The laser generator 53 has a laser control unit 62 and a pulse laser unit 63. The laser introduction unit 55 has a first mirror 64 and a second mirror 65. The X-ray generator constituted as described above generates a monochromatic hard X-ray 68 by colliding the laser light 66 with the electron beam 51 at a collision point 67.
[Patent Document 1] Japanese Patent Application Laid-Open No. 2006-318745
As illustrated in FIG. 2, an X-ray generated by the X-ray generator is detected by an X-ray detector 71. In FIG. 2, reference numeral 72 denotes a collision chamber in which a collision point 67 is set and reference numeral 73 denotes a duct surrounding paths of the electron beam 51 and the laser light 66.
Apart from the X-ray 68 generated by inverse Compton scattering in the above-described X-ray generator, an X-ray 74 generated by braking radiation or an X-ray generated upon collision of the electron beam 51 in a duct 73 exists as noise. To remove this noise, a collimator 75 or a shield 76 is installed around the X-ray detector 71. Since the shield 76 for shielding the noise X-ray must be large, there is a problem in that it is difficult to miniaturize the peripheral of the X-ray detector 71 and therefore a size of the whole device increases. Since the collimator 75 or the shield 76 may not remove the noise X-ray entering the X-ray detector in the same direction as the X-ray 68 generated by inverse Compton scattering, there is a problem in that the S/N ratio may deteriorate.